1. Field
Exemplary embodiments of the present invention relate to a thin film transistor array panel and a manufacturing method thereof. More particularly, exemplary embodiments of the present invention relate to a thin film transistor array panel and a manufacturing method thereof that is capable of forming an insulating layer made of different materials for a portion contacting an oxide semiconductor and the remaining portion without an additional process.
2. Discussion of the Background
A thin film transistor is generally used as a switching element to independently drive each pixel in a flat display device such as a liquid crystal display or an organic light emitting device. A thin film transistor array panel including the thin film transistor includes a scanning signal line (or a gate line) for transmitting a scanning signal to the thin film transistor and a data line for transmitting a data signal, as well as a pixel electrode connected to the thin film transistor.
The thin film transistor includes a gate electrode that is connected to the gate line, a source electrode that is connected to the data line, a drain electrode that is connected to the pixel electrode, and a semiconductor layer that is disposed on the gate electrode between the source electrode and drain electrode, and the data signal is transmitted to the pixel electrode from the data line according to the gate signal from the gate line.
In this case, the semiconductor layer of the thin film transistor includes polysilicon, amorphous silicon, or an oxide semiconductor.
Recently, an oxide semiconductor using a metal oxide having a low cost and high uniformity compared with polycrystalline silicon as well as high charge mobility and a high ON/OFF ratio of current compared with amorphous silicon has been researched.
When forming the semiconductor layer of the thin film transistor by using the oxide semiconductor, if the insulating layer of the portion contacting the oxide semiconductor is made of silicon nitride, the oxide semiconductor may deteriorate due to characteristics of the oxide semiconductor. Also, if the insulating layer contacting the metal layers is formed with silicon oxide, the metal layer may deteriorate.
As described above, when forming the insulating layer by using the same material at the portion contacting the oxide semiconductor and the metal layer, the characteristic of the thin film transistor may deteriorate.
The above information disclosed in this Background section is to enhance the understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.